$OpenBSD: patch-simgear_compiler_h,v 1.2 2016/09/19 22:38:50 pascal Exp $
--- simgear/compiler.h.orig	Thu Sep  8 08:52:42 2016
+++ simgear/compiler.h	Mon Sep 19 16:14:31 2016
@@ -184,7 +184,8 @@ inline int (isnan)(double r) { return !(r <= 0 || r >=
 #  define SG_WINDOWS
 #endif
 
-#if defined(__linux__) || defined(_AIX) || defined ( sgi )
+#if defined(__linux__) || defined(_AIX) || defined ( sgi ) || \
+	defined(__OpenBSD__)
 #  define SG_UNIX
 #endif
 
